Article of manufacture for turbomachine

ABSTRACT

An article of manufacture is provided having a first component configured for use with a stator of a turbomachine. The first component is configured for attachment to a second component. The second component is also configured for use with the stator of the turbomachine. The first component is configured to substantially reduce the possibility of installation in an undesired stage of the stator by modification of at least one characteristic of the first component. The second component is configured to substantially reduce the possibility of installation in an undesired stage of the stator by modification of at least one characteristic of the second component.

BACKGROUND OF THE INVENTION

The present invention relates generally to turbomachinery, and moreparticularly relates to an article of manufacture configured for usewith turbomachines.

A conventional gas turbine generally operates on the principle ofcompressing air within a compressor, and then delivering the compressedair to a combustion chamber where fuel is added to the air and ignited.Afterwards, the resulting combustion mixture is delivered to the turbinesection of the engine, where a portion of the energy generated by thecombustion process is extracted by a turbine to drive the compressor viaa shaft.

In multi-stage compressor sections, stators vanes are placed at theentrance and exit of the compressor section, as well as between eachcompressor stage, for purposes of properly directing the airflow to eachsuccessive compressor stage. As a result, stator vanes are able toenhance engine performance by appropriately influencing air flow andpressure within the compressor section.

Each stator stage generally consists of an annular array of airfoils, orvanes. A stator stage is typically formed in segments as stator vaneunits consisting of one or more airfoils supported by the base. Thesestator vane units are then individually mounted to the compressor casingto form an annular array, so that the airfoils project radially betweenan adjacent pair of rotor stages.

Stator vanes in an industrial gas turbine compressor are loaded andunloaded during start-stop cycles. In addition, the vanes are subject tosmall pressure fluctuations during operation. These result in relativemotion between the vane base and the casing in which the vanes areassembled. The relative motion results in wear of both the vane base andcasing, which, in turn, results in loose vanes. The loose vanes becomemore susceptible to relative motion and begin to chatter. Repair orreplacement of the vanes may be required. Similar problems exist betweenstator ring segments, which hold a plurality of stator vanes, the statorring segments being mounted in slots of the compressor casing.

FIG. 1 illustrates a known compressor section 10 showing a portion of anopen casing 15 of a compressor showing five exemplary stages (rows) 20a-20 e of stator vanes 25. In the embodiment shown, the casing section15 is semicircular. The casing 15 has a mounting surface 30 that may besecured to a corresponding mounting surface on another casing sectionwith fasteners extending through a plurality of holes 35. For a completecompressor, two of the semicircular casing sections would be fittedtogether around a rotor (not shown).

Each stator vane 25 has an airfoil 40 that extends upwards from a base45 and radially inward towards the shaft of the compressor rotor (notshown). The airfoil 40, and stator vanes 25, are interposed between therotor blades (not shown). Certain stator stages of a compressor maymount stator vanes directly in a slot in the casing. Other stator stagesmount stator vanes in ring segments, which are then mounted in slots ofthe casing.

FIG. 2 illustrates individual stator vanes 25. Airfoil 40 extendsvertically from a base or platform 45. The base 45 has two opposingretaining faces 50. The base 45 has a pair of projections 55, one oneach of the retaining faces. The projections 55 are to be received by acorrespondingly shaped groove in a slot of the casing. The groovesretain the stator vane 25 in place in the slot of the casing. The othertwo opposing faces of the base 45 are the engaging faces 60. Theengaging faces 60 of base 45 butt against the bases 45 of adjacentstator vane units when the units are installed in a casing slot. Theretaining faces 50 and projections 55 are the same shape and size onboth sides of the stator vane 25. In this arrangement, the stator vanes25 can be rotated 180 degrees and inserted within a casing slot (or ringsegment).

FIG. 3 illustrates an enlarged side view of the casing showing a stagein which individual stator vanes are assembled in a slot of thecompressor casing. For this type of installation, a plurality of thestator vanes 25 are assembled in the casing to form the stator vanestage. The casing 15 has a plurality of slots 70 for receiving thestator vane units 25. The slot 70 has a pair of side edges 75, whicheach has a groove or dovetail-shaped recess 80. The square base dovetail80 holds the vane units 25 in place. The side edges 75 and dovetails 80are mirror images of each other on each side of the slot. As mentionedpreviously, this allows the stator vanes 25 to be rotated 180 degreesand inserted within a casing slot (or ring segment), with the potentialfor inserting a stator vane backwards. The term “backwards” is definedas the airfoil being oriented 180 degrees from a desired orientation.Each vane unit 25 is allowed to slide into place with the base 45received in the slot 70 and the projections 55 received in the grooves80. The casing 15 in the particular example shown has an air extractioncavity 85 that underlies the stage and is formed by the slot 70 and thestator vanes 25.

The stator vanes 25 for an individual stage are sequentially placed inthe slot 70 of the casing 15 until the full circumferential run of theslot has been filled with a designated number of stator vanes.

Other stages of stator vanes may be attached to the casing using ringsegment assemblies. The ring segment assembly includes a ring segmentand one or more stator vanes. Ring segments typically hold a pluralityof stator vanes. After the ring segments have been loaded with statorvanes, the ring segments are slid into circumferential slots in theturbine/compressor casing and are butted against each other tosequentially fill the circumferential slots. Blades that are larger andhave more forces placed on them may be assembled using this vane andring segment assembly to provide a stiffer base mount.

FIG. 4 illustrates a ring segment assembly 400 that is slid out and awayfrom the casing 15. The ring segment 90 receives a plurality of statorvanes 25. A base 45 of the stator vane 25 slides (in a generally axialdirection with respect to the compressor) into the ring segment 90. Thebase 45 of the stator vane 25 includes a dovetail 95 fitting into andbeing retained by a corresponding dovetail-shaped slot 100 in the ringsegment 90.

The ring segment 90 slides into the circumferential slot 70 of thecasing 15. The sidewalls 105 of the ring segment 90 are supportedaxially by the sidewalls 110 of the slot 70 when the ring segment 90 iswithin the slot 70. The square base dovetail 115 of the ring segment 90fits into the grooves 120 of the circumferential slot 70, therebyretaining the ring segments 90 in the circumferential slot 70. Ringsegments 90 are sequentially placed in the slot 70 of casing 15 untilthe slot 70 is filled with the design number of ring segment assemblies.

During initial assembly of turbomachine components, or subsequent repairand replacement of turbomachine components, a large number of componentsmust be installed in specific locations of the turbomachine. Forexample, a stage one stator vane must be installed in the correctposition in a stage one stator case. A typical turbomachine may havemany stages with many corresponding components, so a high probabilityexists that a component for a specific stage may get installed in anincorrect stage (e.g., a stage five stator vane might get installed in astage six stator slot). The negative implications of this event lead tomachine malfunction or inefficiency and increase outage or constructiontime due to the need to remove and correctly install the specificcomponents. Accordingly, a need still exists for an improved system forinstalling turbomachine components that reduces the probability forerrors during installation.

BRIEF DESCRIPTION OF THE INVENTION

According to one aspect of the present invention, an article ofmanufacture is provided having a first component configured for use witha stator of a turbomachine. The first component is configured forattachment to a second component. The second component is alsoconfigured for use with the stator of the turbomachine. The firstcomponent is configured to substantially reduce the possibility ofinstallation in an undesired stage of the stator by modification of atleast one characteristic of the first component. The second component isconfigured to substantially reduce the possibility of installation in anundesired stage of the stator by modification of at least onecharacteristic of the second component.

According to another aspect of the present invention, an article ofmanufacture is provided having a first component configured for use witha stator of a turbomachine. The first component is configured forattachment to a second component, and the second component is configuredfor use with the stator of the turbomachine. A third component isconfigured for use with the stator of the turbomachine, and the thirdcomponent is configured for attachment to the second component. Thefirst component is configured to substantially reduce the possibility ofinstallation in an undesired stage of the stator by modification of atleast one characteristic of the first component. The second component isconfigured to substantially reduce the possibility of installation in anundesired stage of the stator by modification of at least onecharacteristic of the second component. The third component isconfigured to substantially reduce the possibility of installation in anundesired stage of the stator by modification of at least onecharacteristic of the third component.

According to yet another aspect of the present invention, an article ofmanufacture configured for use with a turbomachine is provided. Thearticle of manufacture includes a stator having an upper half and alower half. The upper half has one or more upper half locker segmentsand a plurality of upper half pack segments. The plurality of upper halfpack segments are located circumferentially between the one or moreupper half locker segments. The lower half has one or more lower halflocker segments and a plurality of lower half pack segments. Theplurality of lower half pack segments are located circumferentiallybetween the one or more lower half locker segments. At least onecharacteristic of the upper half is different than at least onecharacteristic of the lower half.

These and other features and improvements of the present inventionshould become apparent to one of ordinary skill in the art upon reviewof the following detailed description when taken in conjunction with theseveral drawings and the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a compressor section including a portion of an opencompressor casing showing five exemplary stages of stator vanes;

FIG. 2 illustrates individual stator vanes;

FIG. 3 illustrates a stator vane assembled in a slot of a turbinecasing;

FIG. 4 illustrates a ring segment assembly slid out from the turbinecasing slot;

FIG. 5 illustrates an axial compressor flow path, according to an aspectof the invention;

FIG. 6 illustrates a partial, cross-sectional view of a stator casing,according to an aspect of the invention;

FIG. 7 illustrates a perspective view of a plurality of stator vanesinserted in a ring segment, according to an aspect of the invention;

FIG. 8 illustrates a cross-sectional view of a stator vane, according toan aspect of the invention; and

FIG. 9 illustrates a schematic representation of a stator, according toan aspect of the invention.

DETAILED DESCRIPTION OF THE INVENTION

One or more specific aspects/embodiments of the present invention willbe described below. In an effort to provide a concise description ofthese aspects/embodiments, all features of an actual implementation maynot be described in the specification. It should be appreciated that inthe development of any such actual implementation, as in any engineeringor design project, numerous implementation-specific decisions must bemade to achieve the developers' specific goals, such as compliance withmachine-related, system-related and business-related constraints, whichmay vary from one implementation to another. Moreover, it should beappreciated that such a development effort might be complex and timeconsuming, but would nevertheless be a routine undertaking of design,fabrication, and manufacture for those of ordinary skill having thebenefit of this disclosure.

When introducing elements of various embodiments of the presentinvention, the articles “a,” “an,” “the,” and “said” are intended tomean that there are one or more of the elements. The terms “comprising,”“including,” and “having” are intended to be inclusive and mean thatthere may be additional elements other than the listed elements. Anyexamples of operating parameters and/or environmental conditions are notexclusive of other parameters/conditions of the disclosed embodiments.Additionally, it should be understood that references to “oneembodiment”, “one aspect” or “an embodiment” or “an aspect” of thepresent invention are not intended to be interpreted as excluding theexistence of additional embodiments or aspects that also incorporate therecited features. A turbomachine is defined as a machine that transfersenergy between a rotor and a fluid or vice-versa, including but notlimited to gas turbines, steam turbines and compressors.

Referring now to the drawings, FIG. 5 illustrates an axial compressorflow path 500 of a compressor 501 that includes a plurality ofcompressor stages. The compressor 501 may be used in conjunction with,or as part of, a gas turbine. As one non-limiting example only, thecompressor flow path 500 may comprise about eighteen rotor/statorstages. However, the exact number of rotor and stator stages is a choiceof engineering design, and may be more or less than the illustratedeighteen stages. It is to be understood that any number of rotor andstator stages can be provided in the compressor, as embodied by theinvention. The eighteen stages are merely exemplary of oneturbine/compressor design, and are not intended to limit the inventionin any manner.

The compressor rotor blades 502 impart kinetic energy to the airflow andtherefore bring about a desired pressure rise. Directly following therotor blades 502 is a stage of stator vanes 504. However, in somedesigns the stator vanes 504 may precede the rotor blades 502. Both therotor blades 502 and stator vanes 504 turn the airflow, slow the airflowvelocity (in the respective airfoil frame of reference), and yield arise in the static pressure of the airflow. Typically, multiple rows ofrotor/stator stages are arranged in axial flow compressors to achieve adesired discharge to inlet pressure ratio. Each rotor blade and statorvane includes an airfoil, and these airfoils can be secured to rotorwheels or a stator case by an appropriate attachment configuration,often known as a “root,” “base” or “dovetail”. In addition, compressorsmay also include inlet guide vanes (IGVs) 506, variable stator vanes(VSVs) 508 and exit or exhaust guide vanes (EGVs) 510. All of theseblades and vanes have airfoils that act on the medium (e.g., air)passing through the compressor flow path 500.

Exemplary stages of the compressor 501 are illustrated in FIG. 5. Onestage of the compressor 501 comprises a plurality of circumferentiallyspaced rotor blades 502 mounted on a rotor wheel 512 and a plurality ofcircumferentially spaced stator vanes 504 attached to a staticcompressor case 514. Each of the rotor wheels 512 may be attached to anaft drive shaft 516, which may be connected to the turbine section ofthe engine. The rotor blades and stator vanes lie in the flow path 500of the compressor 501. The direction of airflow through the compressorflow path 500, as embodied by the invention, is indicated by the arrow518 (FIG. 5), and flows generally from left to right in theillustration.

The rotor blades 502 and stator vanes 504 herein of the compressor 501are merely exemplary of the stages of the compressor 502 within thescope of the invention. In addition, each inlet guide vane 506, rotorblade 502, stator vane 504, variable stator vane 508 and exit guide vane510 may be considered an article of manufacture. Further, the article ofmanufacture may comprise a stator vane and/or a stator casing and/or aring segment configured for use with a compressor.

Aspects of the present invention provide a collection of strategicallydefined geometric features incorporated on the stator vanes, ringsegments (also referred to as stator vane attachments), and casing slotsfor a unique configuration of the stator vane assembly. This uniqueconfiguration prevents mis-assembly due to assembly errors. Assemblyerrors occur when a stator vane or ring segment is installed in thewrong stage or the wrong half of the casing. For example, a stator vaneor ring segment may be designed for an upper half of the compressor, butassembly error leads to installion in the lower half of the compressor.Further, this unique configuration provides a physical method ofmis-assembly proofing where the wrong method of installion may not bevisually apparent. For example, it would be difficult to place a stagefive stator vane in a stage thirteen stator slot, however, it would bevery easy to interchange (and install incorrectly) a stage eleven statorvane with a stage twelve stator vane. Adjacent stages may have verysimilarly sized components, and even though these sizes may lookvisually insignificant (or hard to detect), the improper installation ofcomponents can lead to severe machine damage and loss of efficiency.

FIG. 6 illustrates a partial, cross sectional view of a stator casing600, according to an aspect of the present invention. In this example, aring segment 602, shown in phantom, is positioned within the statorcasing slot 604. The stator casing slot has an axial length 605 whichmay be the distance between the forward sidewall 606 and the aftsidewall 607. Alternatively, the axial length 610 may be measured fromthe forward and aft surfaces of the forward groove 612 and aft groove613. The stator casing slot also has two radial heights. The radialheight 620 of the forward sidewall 606 may be measured from the bottomof slot 604 to the top of forward sidewall 606. The radial height 630 ofthe aft sidewall 607 may be measured from the bottom of slot 604 to thetop of aft sidewall 607. According to an aspect of the presentinvention, the forward radial height 620 may be configured to bedifferent from the aft radial height 630, and in the example shown theforward radial height 620 is smaller than the aft radial height 630.Further, the radial height of the forward groove 612 may be differentthan the radial height of the aft groove 613. The radial positioning ofthe forward and aft grooves may also be different.

It is to be understood that the invention is not to be limited to onlythe examples shown, and that the invention also includes embodimentswhere the aft groove has a smaller radial height than the forward radialgroove, the forward and aft radial grooves have different axial depths,the forward and aft radial grooves have different geometricalcross-sectional shapes and/or the forward and aft radial grooves havedifferent radial heights or are located at different radial heights. Itis also to be understood that the invention also includes embodimentswhere the forward sidewall has a larger radial height than the aftsidewall.

FIG. 7 illustrates a perspective view of a plurality of stator vanes 710inserted in a ring segment 720, according to an aspect of the presentinvention. The ring segment 720 fits into the stator slot (e.g., slot604 in FIG. 6). The ring segment 720 has an axial length 730, which maybe measured from the forward sidewall or forward surface 732 to the aftsidewall or aft surface 734, or the axial length 730 may be measuredfrom the end of the forward projection 736 to the end of the aftprojection 738. According to an aspect of the present invention, thisaxial length 730 may be configured so that it is different for eachstage of the stator, for adjacent stages of the stator, or for nearbystages of the stator. This configuration provides the advantage ofeliminating the possibility of a ring segment designed for a specificstage from being installed in an adjacent or nearby stage of the stator.For example, the axial length 730 for a stage five ring segment may be 3inches, and the axial length for a stage six ring segment may be 2.75inches, so it would be impossible to insert the stage five ring segmentinto a stage six stator casing slot, because the stage six stator casingslot would be too small.

Ring segments may also be installed backwards when the cross-sectionalprofile of the ring segment is symmetrical. When this happens, machineefficiency is reduced and damage may occur. According to another aspectof the present invention, the ring segment 720 has a generallytrapezoidal or quadrilateral cross-sectional profile. The radial height740 of the forward sidewall/surface 732 is configured to be differentthan the radial height 742 of the aft sidewall/surface 734, and theseheights may be measured from the base of the respective sidewalls orfrom the bottom surface of the ring segment. The radial height 740 isshown to be smaller than radial height 742, but it is to be understoodthat the radial height 740 could also be configured to be larger thanradial height 742.

In addition, the radial height 744 of the forward projection 736 may beconfigured to be smaller than the radial height 746 of the aftprojection 738. As one example only, the radial height 744 of theforward projection 736 may be about 0.25 inches while the radial height746 of the aft projection 738 may range between about 0.30 inches andabout 0.50 inches. The purpose of the difference in radial heights(between forward and aft projections) is to ensure that the ring segment720 is not installed backwards in the stator casing slot. Further,adjacent or nearby stages may have different radial heights for the aftprojection (and/or different radial heights for the forward projection)to further error-proof installation.

FIG. 8 illustrates a cross-sectional view of a stator vane 800,according to an aspect of the present invention. The stator vane 800 maybe configured to fit directly into a stator casing slot or into a ringsegment, where the ring segment is configured to engage a stator casingslot. The stator vane 800 has an angled platform 810 that tapers up froma forward side 801 to an aft side 802. However, the platform could alsobe configured to taper downward from the forward side to the aft side ofthe stator vane. This taper ensures that the stator vane 800 can only beinserted in the designed direction on the ring segment or stator casingslot, and that backwards installation is impossible. In order toproperly match the complementary surfaces of the ring segment or statorcasing slot, the forward surface or forward sidewall 811 is configuredto have a smaller radial height 821 than the radial height 822 of theaft surface or aft sidewall 812. The lower dovetail or tang portion 830is configured to fit within the lower portion of the ring segment slot.The upper dovetail 840 is tapered to follow the contours of the platform810 and to allow insertion into the ring segment or stator casing slot.The axial length 850 of the stator vane 800 may also be configured to bedifferent for each stage or for adjacent or nearby stages to reduce oreliminate the possibility of installation in an undesired stage ringsegment or stator casing slot.

FIG. 9 illustrates a schematic representation of a stator, according toan aspect of the present invention. The stator 900 may be divided intomany arcuate sections or segments. An upper half 901 may include anupper half left half locker segment 911, an upper half right half lockersegment 912, and a plurality of n-pack segments 913-916. However, it isto be understood that more or less n-pack segments could be used asdesired in the specific application. Each of the n-pack segments span anangle of θn and have a circumferential length or arc length of ARCn. θnmay be referred to as the span angle. The upper half n-segments may bereferred to collectively as the n-Pack.

A lower half 902 may include a lower half left half locker segment 921,a lower half right half locker segement 922, and a plurality of m-packsegments 923-929. However, it is to be understood that more or lessm-pack segments could be used as desired in the specific application, aslong as there are a different number of n and m pack segments. Each ofthe m-pack segments span an angle of θm and have a circumferentiallength or arc length of ARCm. θm may be referred to as the span angle.The lower half m-segments may be referred to collectively as the m-Pack.

According to an aspect of the present invention, and to aid in foolproofing installation of stator components, the stator has a differentnumber of n-pack segments than m-pack segments. As shown, there arefewer n-pack segments than m-pack, but this could be reversed to havemore m-pack segments than n-pack segments as desired in the specificapplication. The angle of θn is also configured to be different than theangle θm, and in the example shown θn is greater than θm. However, it isto be understood that in some applications it may be desirable to haveθm be greater than θn. The difference in angles also leads to adifference in segment arc length, as the arc length ARCn is greater thanthe arc length ARCm. However, it is to be understood that in someapplications it may be desirable to have ARCm be greater than ARCn.

According to an aspect of the present invention, an article ofmanufacture configured for use with a turbomachine has a stator 900having an upper half 901 and a lower half 902. The upper half 901 hasone or more upper half locker segments 911, 912 and a plurality of upperhalf pack segments 913-916. The upper half pack segments 913-916 arelocated circumferentially between the one or more upper half lockersegments 911, 912. The lower half 902 has one or more lower half lockersegments 921, 922 and a plurality of lower half pack segments 923-929.The lower half pack segments 923-929 are located circumferentiallybetween the lower half locker segments 921, 922. At least onecharacteristic of the upper half 901 is different than at least onecharacteristic of the lower half 902. The characteristics of both theupper half 901 and lower half 902 are chosen from one, all or a portionof, the number of pack segments, the pack segment span angle θn or m,and pack segment arc length ARCn or ARCm.

The various features of the stator, according to an aspect of thepresent invention, are used to fool proof installation of statorcomponents. It can be seen that by physically changing the statorsegments so that the number of n-pack segments are different from thenumber of m-pack segments, configuring the angle θn to be different fromthe angle θm and by configuring the arc length ARCn to be different thanthe arc length ARCm, that it is now extremely difficult, if notimpossible, to improperly install the stator components.

Aspects of the present invention provide, an article of manufacturecomprising a first component (e.g., stator vane 800) configured for usewith a stator of a turbomachine. The first component (e.g., stator vane800) is configured for attachment to a second component (e.g., ringsegment 720) also configured for use with the stator of theturbomachine. The first component (e.g., stator vane 800) is configuredto substantially reduce the possibility of installation in an undesiredstage of the stator by modification of at least one characteristic ofthe first component. The second component (e.g., ring segment 720) isconfigured to substantially reduce the possibility of installation in anundesired stage of the stator by modification of at least onecharacteristic of the second component.

The characteristic of the stator vane 800 may be chosen from one, all,or a portion of, the radial height 821 of a forward sidewall 811, theradial height 822 of an aft sidewall 812, and an axial length 850. Thecharacteristic of the ring segment 720 may be chosen from one, all, or aportion of, the radial height 740 of a forward surface 732, the radialheight 742 of an aft surface 734, the radial height 744 of a forwardprojection 736, the radial height 746 of an aft projection 738, and anaxial length 730.

The article of manufacture may also include a third component (e.g.,stator casing slot 604) configured for use with the stator of theturbomachine. The third component is also configured for attachment tothe second component (e.g., ring segment 720). The third component(e.g., stator casing slot 604) is configured to substantially reduce thepossibility of installation in an undesired stage of the stator bymodification of at least one characteristic of the third component. Thecharacteristic of the stator casing slot 604 may be chosen from one,all, or a portion of, the radial height 620 of a forward sidewall 606, aradial height 630 of an aft sidewall 607, a radial height of a forwardgroove 612, a radial height of an aft groove 613, and an axial length605 or 610.

This written description uses examples to disclose the invention,including the best mode, and also to enable any person skilled in theart to practice the invention, including making and using any devices orsystems and performing any incorporated methods. The patentable scope ofthe invention is defined by the claims, and may include other examplesthat occur to those skilled in the art. Such other examples are intendedto be within the scope of the claims if they have structural elementsthat do not differ from the literal language of the claims, or if theyinclude equivalent structural elements with insubstantial differencesfrom the literal languages of the claims.

1. An article of manufacture comprising: a first component configuredfor use with a stator of a turbomachine, the first component configuredfor attachment to a second component, the second component configuredfor use with the stator of the turbomachine: wherein, the firstcomponent is configured to substantially reduce the possibility ofinstallation in an undesired stage of the stator by modification of atleast one characteristic of the first component, and the secondcomponent is configured to substantially reduce the possibility ofinstallation in an undesired stage of the stator by modification of atleast one characteristic of the second component.
 2. The article ofmanufacture of claim 1, wherein the first component is a stator vane andthe second component is a ring segment.
 3. The article of manufacture ofclaim 2, the at least one characteristic of the stator vane comprisingat least one of: a radial height of a forward sidewall, a radial heightof an aft sidewall, and an axial length.
 4. The article of manufactureof claim 2, the at least one characteristic of the ring segmentcomprising at least one of: a radial height of a forward surface, aradial height of an aft surface, a radial height of a forwardprojection, a radial height of an aft projection, and an axial length.5. The article of manufacture of claim 1, further comprising: a thirdcomponent configured for use with the stator of the turbomachine, thethird component configured for attachment to the second component;wherein, the third component is configured to substantially reduce thepossibility of installation in an undesired stage of the stator bymodification of at least one characteristic of the third component. 6.The article of manufacture of claim 5, wherein the third component is astator casing slot; and wherein the at least one characteristic of thestator casing slot is at least one of, a radial height of a forwardsidewall, a radial height of an aft sidewall, a radial height of aforward groove, a radial height of an aft groove, and an axial length.7. An article of manufacture comprising: a first component configuredfor use with a stator of a turbomachine, the first component configuredfor attachment to a second component, the second component configuredfor use with the stator of the turbomachine; a third componentconfigured for use with the stator of the turbomachine, the thirdcomponent configured for attachment to the second component; wherein,the first component is configured to substantially reduce thepossibility of installation in an undesired stage of the stator bymodification of at least one characteristic of the first component, thesecond component is configured to substantially reduce the possibilityof installation in an undesired stage of the stator by modification ofat least one characteristic of the second component, and the thirdcomponent is configured to substantially reduce the possibility ofinstallation in an undesired stage of the stator by modification of atleast one characteristic of the third component.
 8. The article ofmanufacture of claim 7, wherein the first component is a stator vane,the second component is a ring segment and the third component is astator casing slot.
 9. The article of manufacture of claim 8, the atleast one characteristic of the stator vane comprising at least one of:a radial height of a forward sidewall, a radial height of an aftsidewall, and an axial length.
 10. The article of manufacture of claim8, the at least one characteristic of the ring segment comprising atleast one of: a radial height of a forward surface, a radial height ofan aft surface, a radial height of a forward projection, a radial heightof an aft projection, and an axial length.
 11. The article ofmanufacture of claim 8, the at least one characteristic of the statorcasing slot comprising at least one of: a radial height of a forwardsidewall, a radial height of an aft sidewall, a radial height of aforward groove, a radial height of an aft groove, and an axial length.12. The article of manufacture of claim 8, wherein the turbomachine is acompressor.
 13. The article of manufacture of claim 1, furthercomprising: the stator having an upper half and a lower half; the upperhalf having one or more upper half locker segments and a plurality ofupper half pack segments, the plurality of upper half pack segmentslocated circumferentially between the one or more upper half lockersegments; the lower half having one or more lower half locker segmentsand a plurality of lower half pack segments, the plurality of lower halfpack segments located circumferentially between the one or more lowerhalf locker segments; wherein at least one characteristic of the upperhalf is different than at least one characteristic of the lower half.14. The article of manufacture of claim 13, wherein the at least onecharacteristic of both the upper half and the lower half are chosen fromat least one of: a number of pack segments, pack segment span angle, andpack segment arc length.
 15. An article of manufacture configured foruse with a turbomachine, the article of manufacture comprising: a statorhaving an upper half and a lower half; the upper half having one or moreupper half locker segments and a plurality of upper half pack segments,the plurality of upper half pack segments located circumferentiallybetween the one or more upper half locker segments; the lower halfhaving one or more lower half locker segments and a plurality of lowerhalf pack segments, the plurality of lower half pack segments locatedcircumferentially between the one or more lower half locker segments;wherein at least one characteristic of the upper half is different thanat least one characteristic of the lower half.
 16. The article ofmanufacture of claim 15, wherein the at least one characteristic of boththe upper half and the lower half are chosen from at least one of: anumber of pack segments, pack segment span angle, and pack segment arclength.
 17. The article of manufacture of claim 15 further comprising: afirst component configured for use with a stator of a turbomachine, thefirst component configured for attachment to a second component, thesecond component configured for use with the stator of the turbomachine;wherein, the first component is configured to substantially reduce thepossibility of installation in an undesired stage of the stator bymodification of at least one characteristic of the first component, andthe second component is configured to substantially reduce thepossibility of installation in an undesired stage of the stator bymodification of at least one characteristic of the second component. 18.The article of manufacture of claim 17, wherein the first component is astator vane and the second component is a ring segment; and the at leastone characteristic of the stator vane is chosen from at least one of, aradial height of a forward sidewall, a radial height of an aft sidewall,and an axial length; and the at least one characteristic of the ringsegment is chosen from at least one of, a radial height of a forwardsurface, a radial height of an aft surface, a radial height of a forwardprojection, a radial height of an aft projection, and an axial length.19. The article of manufacture of claim 17, further comprising: a thirdcomponent configured for use with the stator of the turbomachine, thethird component configured for attachment to the second component;wherein, the third component is configured to substantially reduce thepossibility of installation in an undesired stage of the stator bymodification of at least one characteristic of the third component. 20.The article of manufacture of claim 19, wherein the third component is astator casing slot; and wherein the at least one characteristic of thestator casing slot is at least one of, a radial height of a forwardsidewall, a radial height of an aft sidewall, a radial height of aforward groove, a radial height of an aft groove, and an axial length.